Field of the Invention
The present invention relates to an image sensor including a plurality of pixels arranged in a matrix, and an image capturing apparatus using the image sensor.
Description of the Related Art
There is conventionally known a technique of capturing images at a high frame rate by providing storage devices for each pixel, and sequentially storing continuously accumulated pixel signals in the storage devices without reading out the pixel signals outside an image sensor.
Japanese Patent Laid-Open No. 2001-345441 discloses a technique of capturing images at a high frame rate by providing a charge signal accumulation unit constituted by charge-coupled devices for each pixel, moving accumulated charges between the charge-coupled devices to sequentially store the charges, and reading them out.
In the conventional technique disclosed by the above-described Japanese Patent Laid-Open No. 2001-345441, however, the area of a pixel becomes large since many storage devices are provided for each pixel, and thus the number of pixels which can be arranged in a limited area becomes small, thereby degrading the image quality. Furthermore, if many storage devices are provided, the area of a photodiode becomes small, and the saturation characteristic and the like decrease, resulting in degradation in image quality.